The present invention relates to image recording and reproducing devices for recording and reproducing dynamic picture and still picture image information onto and from an image recording storage such as a semiconductor memory.
With a rapidly-increasing storage capacity achieved by fine pattern technology for semiconductor memory as well as advancing image compression technology, image recording and reproducing devices have been widely used today which temporarily store image data from a video camera or the like into a semiconductor memory and then reproduce the thus-stored image data from selected locations of the memory at an optional speed. These image recording and reproducing devices are suitable for use in, for example, editing of a TV commercial production and analysis of a form in playing a sport, because of their capability to record a dynamic picture for a period of tens of seconds.
Known as a typical example of such image recording and reproducing devices is a digital video tape recorder (VTR) which is equipped with a photo mode function as well as a movie mode function. When in the photo mode, the digital video tape recorder operates to store, as a still picture frame, a same frame of image information repetitively over a designated time period corresponding to a plurality of frame cycles, because reproduction from the video tape recording would inherently involve unwanted picture distortion. However, because of the repetitive storage of the same frame, the digital video tape recorder in the photo mode would present the problem that its limited storage space is wasted and thus the amount of still picture image information and dynamic picture image information recordable therein is considerably limited. Particularly, in cases where a semiconductor memory is employed, the recordable information amount is even more limited than where other forms of storage media are employed, and it is necessary that still picture image information be stored in the storage space with utmost efficiency.
In addition, a video signal recording device has been proposed in Japanese Patent Laid-open Publication A. No. HEI-5-308606, which is designed to record still picture image information on a PCM recording area of a video tape separate from a dynamic picture recording area of the tape. In reproduction, this recording device writes the still picture image information into a video RAM-and repetitively reproduces the thus-written information until next still picture image information is read in. However, the proposed video signal recording device, where dynamic picture image information and still picture image information is stored separately in the respective recording areas, is disadvantageous in that the recording capacity can not be used efficiently as a whole when only dynamic picture image information or still picture image information is recorded and also in that very complex management of reproduction addresses is required when the stored dynamic picture and still pictures are to be reproduced in succession.
It is therefore an object of the present invention to provide an improved image recording and reproducing device which permits efficient use of an image storage area, and which can optimally reproduce both dynamic picture image information and still picture image information stored together in a mixed manner without requiring complex management.
According to an aspect of the present invention, there is provided an image recording and reproducing device which comprises: an image storage section for storing therein image information including dynamic picture image information and still picture image information; a recording section that stores time-varying frames of the dynamic picture image information and a frame of the still picture image information into a same storage area of the image storage section together in a mixed manner; and a reproducing section that identifies the individual frames of the dynamic picture image information and the still picture image information stored in the image storage section and reproduces the identified frames of the dynamic picture image information and the still picture image information at reproduction speeds that are set separately for the dynamic picture image information and the still picture image information.
Because the frames of the dynamic picture image information and the still picture image information are stored together in a same storage area of the image storage section in a mixed form, the present invention can use the entire storage area of the storage section very efficiently, as compared to cases where separate storage areas are fixedly allocated for the dynamic picture image information and the still picture image information. Also, in the present invention, the frames of the dynamic picture image information and the still picture image information can be read out in succession without a particular need to distinguish between the dynamic picture image information and the still picture image information, which would substantially simplify address management involved in readout or reproduction of the frames. Further, in the present invention, only one frame is stored for each item of the still picture image information, it is possible to minimize the necessary storage space for the still picture image information. In addition, because the individual frames of the dynamic picture and still picture image information are identified as such and reproduced at respective or independently-set reproduction speeds, the present invention can provide optimum reproduced pictures for both the dynamic picture and still picture image information.
In an preferred implementation of the present invention, the recording section adds, to the frames of the dynamic picture image information and the still picture, respective attribute information for identifying the frames, and the reproducing section identifies the individual frames of the dynamic picture image information and the still picture image information on the basis of the respective attribute information added thereto. By such addition of the attribute information to the individual frames, it is possible to readily distinguish between the frame of the dynamic picture image information and the frame of the still picture image information.
In another preferred implementation of the present invention, the image recording and reproducing device further comprises a still-picture reproduction period setting section that sets a reproduction period for the still picture image information, and the reproducing section reproduces the identified frame of the still picture image information repetitively for the reproduction period set by the still-picture reproduction period setting section. With the arrangement of repetitively reproducing an identified frame of the still picture, image information for a reproduction period set by the still-picture reproduction period setting section, it is possible to readily perform a process of inserting, between the frames of the dynamic picture image information, a frame of the still picture image information over a desired time period.
Preferably, the image recording and reproducing device further comprises a dynamic-picture reproduction speed setting section that sets a reproduction speed for the dynamic picture image information, and the reproducing section reproduces the identified frames of the dynamic picture image information at the reproduction speed set by the dynamic-picture reproduction speed setting section. In this preferred implementation, the frames of the dynamic picture image information can also be reproduced at a preset reproduction speed.
In still another implementation of the present invention, the image recording and reproducing device as recited further comprises an address designating section that designates an address in the image storage section, and an attribute rewriting section that if a specific one of the frames of the dynamic picture image information stored at the address designated by the address designating section is to be changed to a frame of still-picture image information, rewrites the attribute information of the specific frame. By the attribute information rewriting arrangement, a selected frame of the dynamic picture image information, which may contain some important points of a sports-playing form, can be freely changed to a frame of still picture information and reproduced or displayed as a still picture for a preset period to allow for careful analysis of the important points.
According to another aspect of the present invention, the image recording and reproducing device comprises an image storage section that stores therein image information including dynamic picture image information and still picture image information in such a manner that each frame of the still picture image information is interposed between frames of the dynamic picture image information. The frames of the image information are reproduced in a successive manner, during which time a determination is made, for each of the frames, as to whether the frame is of the dynamic picture image information or of the still picture image information so that each of the frames determined as being of the still picture image information is reproduced repetitively for a preset time period.
Due to the arrangement that the still picture image information is stored in the image storage section in such a manner that each frame of the still picture image information is interposed between frames of dynamic picture image information, and the individual frames of the image information are reproduced in a successive manner while a determination is made, for each of the frames, as to whether the frame in question is of the dynamic picture image information or of the still picture image information so that each of the frames determined as being of the still picture image information is reproduced repetitively for a preset time period, the still picture frame is allowed to be displayed, between the dynamic picture frames, at appropriate timing for an appropriate time period by just storing it at an appropriate location of the storage section. Thus, the present invention permits display of an address telephone number, etc. between commercials.